1. Field of the Invention
The present invention relates to an information recording medium such as a CD or CD-R, and more specifically to an information recording medium to which a label having text and images printed thereon is adhered.
2. Description of the Related Art
As disc-shaped recording media, CD-ROMs (Compact Disc Read Only Memory), CD-Rs (Compact Disc Recordable), CD-RWs (Compact Disc Rewritable), and the like have conventionally been known. CD-ROM is a read-only information recording medium, CD-R is a CD to which recording can be performed once, and CD-RW is a rewritable CD.
CD-ROMs are usually shipped with indexes such as the recorded content, its title and the like printed directly by the manufacturer on the surface opposite the surface from which data is read. However, in the case of CD-Rs and CD-RWs on which users can record data, there are cases where the user prints information such as the recorded content and title, and further, image data such as graphics and photographs on a label, and adheres the label onto the CD-R, for example, with an adhesive. The same applies to DVDs (Digital Versatile Disc).
As related art, there exists a method in which a label is positioned in relation to a positioning sheet placed inside a recess and brought into close contact with the positioning sheet. The label has a transparent film layer on which an image is printed, an adhesive layer, and a release sheet that are layered. After the release sheet is peeled off to expose the adhesive layer, a recording medium is fit inside the recess, and the label is adhered onto the recording medium (see, for example, Japanese Patent Application Publication No. 2000-222857, pages 4 to 5, and FIGS. 5 through 12).
However, when a label made of a specific material is adhered onto, for example, a CD-R, if an adhesive is applied to the entire surface of the label surface (the surface on the side opposite the side on which data is recorded), under an environment in which the temperature fluctuates widely, such as inside a car, due to so-called bi-metal effects, the CD-R may become bent or deformed by, for example, 1.5° which exceeds the permissible range of skew of ±0.6°, and data may become unreadable, thus presenting a technical problem.
In the technique disclosed in Japanese Patent Application Publication No. 2000-222857 mentioned above, there is not disclosed any effective technique for preventing bending or deformation caused by temperature variation and which exceeds the permissible range of skew.